<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>css基本语法</title>
     <!-- 链接css文件 -->
     <link rel="stylesheet" href="css/style.css">
</head>
<body>
    <div id="box1">这是一个div</div>
    <div id="box2">这是一个div</div>
    <div id="box3">这是一个div</div>
</body>
</html>